I have used Pann's services for decades, first to purchase and install hot water tanks, then for all my plumbing services. Their technicians arrive in clean clothes, use shoe mitts, and are pleasant to work with. Most of the time, they are able to accurately diagnose the problem and to correct it. To their credit, if a residual problem exists or manifests at a later date, they are fully cooperative, both in making corrective efforts and in price adjustments. I continue to utilize them on a regular basis because their technicians are well-trained and the company dependable.
Pann is inordinately expensive, though, for some of their services, particularly the non-plumbing variety. However, I've elected to be on their "Peace of Mind" plan which is a pre-paid monthly service contract offering better terms and discounts.